114 lines
2.7 KiB
C++
114 lines
2.7 KiB
C++
/*
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* Copyright (C) 2016 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef LIBMEMUNREACHABLE_SCOPED_DISABLE_MALLOC_H_
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#define LIBMEMUNREACHABLE_SCOPED_DISABLE_MALLOC_H_
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#include <memory>
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#include "android-base/macros.h"
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#include "bionic.h"
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#include "log.h"
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#include "ScopedAlarm.h"
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class DisableMallocGuard{
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public:
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DisableMallocGuard() : disabled_(false){}
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~DisableMallocGuard() {
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Enable();
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}
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void Disable() {
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if (!disabled_) {
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malloc_disable();
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disabled_ = true;
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}
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}
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void Enable() {
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if (disabled_) {
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malloc_enable();
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disabled_ = false;
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}
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}
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private:
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DISALLOW_COPY_AND_ASSIGN(DisableMallocGuard);
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bool disabled_;
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};
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// Any calls to malloc or free from this thread will deadlock as long as this
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// object is in scope. Calls to malloc from other threads may succeed (for
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// example if the allocation is satisfied out of the thread's tcache), or may
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// block until the object is destroyed.
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//
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// Don't call fork() while malloc is disabled, it needs the same locks held
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// here.
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class ScopedDisableMalloc {
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public:
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ScopedDisableMalloc() {
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disable_malloc_.Disable();
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}
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~ScopedDisableMalloc() {
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disable_malloc_.Enable();
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}
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private:
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DISALLOW_COPY_AND_ASSIGN(ScopedDisableMalloc);
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DisableMallocGuard disable_malloc_;
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};
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class ScopedDisableMallocTimeout {
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public:
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ScopedDisableMallocTimeout(std::chrono::milliseconds timeout = std::chrono::milliseconds(2000)) :
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timeout_(timeout), timed_out_(false), disable_malloc_() {
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Disable();
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}
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~ScopedDisableMallocTimeout() {
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Enable();
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}
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bool timed_out() {
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return timed_out_;
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}
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void Enable() {
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disable_malloc_.Enable();
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alarm_ = nullptr;
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}
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void Disable() {
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// set up the alarm before disabling malloc so unique_ptr can be used
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alarm_ = std::make_unique<ScopedAlarm>(timeout_, [&]() {
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disable_malloc_.Enable();
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timed_out_ = true;
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});
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disable_malloc_.Disable();
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}
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private:
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DISALLOW_COPY_AND_ASSIGN(ScopedDisableMallocTimeout);
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std::chrono::milliseconds timeout_;
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bool timed_out_;
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std::unique_ptr<ScopedAlarm> alarm_;
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DisableMallocGuard disable_malloc_;
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};
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#endif // LIBMEMUNREACHABLE_SCOPED_DISABLE_MALLOC_H_
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